The invention relates to a method of producing an optical cable in which at least one optical waveguide fed-forward from a supply reel is provided with a loosely surrounding jacket by means of extrusion, whose length is subsequently reduced relative to the length of the optical waveguide travelling through the extruder and is thereafter wound up.
In a method of this type which is, for example, disclosed in EP-Al 0235753 the sleeve is stretched after extrusion and is then reduced in length by annealing. Reducing the length of the jacket can, however, also be effected by thermal shrinking, as is described in the DE-OS 3425649. In addition, combinations of thermally and elastically induced length reduction are possible. A further change in the length of the jacket can also be effected by crystalline shrinking.
In the known method, the excessive lengths of the optical waveguide(s) can be distributed irregularly along the length of the optical cable. Then there is in particular the risk of the optical waveguides being curved too much in certain regions along its length.